Input csvs containing P and N inventories by HUC8, kgPN from fire retardants per HUC8 x year R code for compiling and matching inputs Output csvs for comparing fire retardant P to P deposition and fire retardant N to N deposition. This dataset is associated with the following publication: Moorhead, L.C., M.J. Pennino, R.D. Sabo, and S.D. LeDuc. Fire Retardants Are an Overlooked Source of Phosphorus to Western US Ecosystems. ACS ES&T Water. American Chemical Society, Washington, DC, USA, 5(4): 1620-1627, (2025).